1. Field of the Invention
The present invention relates to a process for producing a yarn package.
2. Description of Related Art
With yarn packages, i.e., bobbins, particularly those which are used for transportation of yarn and from which the yarn is directly unwound for operations such as knitting or weaving, it is desirable for reasons of economy in distribution and further yarn processing, to wind onto each bobbin package as much yarn as possible, i.e. to produce the most massive packages possible.
These efforts come up against a limit in that, with a very large package radius and especially with the use of fine yarn, the yarn draw-off tension at a constant yarn draw-off speed varies across a wide range. The draw-off tension is very high at the start of an unwinding process since, due to the low rotation generated during drawing off, no sufficiently convex yarn balloon is formed. As a result, the yarn scrapes across the surface of the package, thereby producing high friction.
With large radii, especially for fine yarn, the strain is too great and yarn breakages can readily occur. It has been found that even below the breakage threshold large variations in the yarn draw-off tension should be avoided since tension variations in many cases adversely affect the further processing of the yarn and, particularly in the case of knitted and woven products, lead to inhomogeneities.
Therefore, it is an object of the present invention to provide a manufacturing process for yarn packages, by means of which large, massive packages can be produced, from which the yarn can be drawn off at a constant draw-off speed with uniformly moderate yarn tension, thereby reducing yarn breakages and improving the quality and homogenity of final products.